Brake mechanism



April 7, 1953 E. G. MUELLER 2,633,935

l BRAKE MECHANISM Filed May 29, 1948 3 Sheets-Sheet 2 1 Figi jj, zo@ 110 IN V EN TOR.

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Patented Apr. 7, 1953 i BRAKE MECHANISM Emil G. Mueller, Churchill Borough, Pa., assignor to The American Brake Company, Pa., a corporation of Missouri Swissvale,

Application May 29, 194s, serial No. 30,151

(ci. 18s-46) is claims.

My invention relates to brake mechanism, and

particularly to brake mechanism for applying` clasp brakes to the driving wheels of locomotives'.

In modern high speed locomotives it is frequently desirable to arrange adjacent pairs of driving wheels as closely together as the necessary clearance between the'jwheels themselves will permit in order to keep the overall length of the locomotive to a minimum and thereby facilitate the negotiation of curves. frequently desirable to arrange one or more pairs of driving wheels for lateral movement with respect to the locomotive frame to enable the wheels to freely follow the track rails on curves or uneven stretches of track without undue side-thrust of the wheels on the rails.V

When the driving wheels v arranged closely together in the manner described, there is, of course, nofroom for inserting any part of the brake mechanism directly between the wheels near the horizontal `plane through their centers. Atl the same time available space between the wheels above their centers is frequently limited by the valve gear or other parts of the locomotive, Vwhile the space between the wheels below their centers is limited by the diameters of the wheels'and the necessary track clearance. As a result, if the wheels have relatively small diameters, the only way in which clasp brakes can be applied to the wheels is to place the two shoes which engage the wheels at their contiguouswsides one above and the other below the horizontal plane passing through the wheel centers. With this arrangement the two shoes between the adjacentv closely spaced wheels are oppositely disposed and cooperate with different wheels, thus making it difficult to provide a satisfactory mechanism for .properly operating and supporting the brake shoes.

One object of myinvention is to' provide an improved mechanism which makes it possible to `satisfactorily support and operate clasp brakes for the wheels of a locomotive arranged as above described.

Another object of my'invention is to provide an improved brakehanger assembly capable of supporting the two brake shoes between the adjacent closely spaced driving wheels in such manner that the `minimum permissible spacing between the driving wheels need be no greater than that required for the wheels to clear themselves, andwhich at the same time will permit the brak'efshoesassociated with the laterally movable wheelsto be readily moved laterally a sufcient amount to maintain them in lateral alignment with the wheels- It is also of au locomotive are A furtherobject'of my invention is to provide brake mechanism which can be satisfactorily mounted within the limited space available for the'brake rigging on a locomotive of the type described without interference from or with thef other parts of the locomotive.

Another object of my invention is to kprovide an improved arrangement of brake cylinders and rigging for clasp brakes on a four-wheel truck.

Another object is to provide an improved ar-` rangement for supporting adjacent brake shoesv for cooperation with adjacent wheels of a truck wherein one wheel Vis permitted to move laterally.

withrespect to the truck frame and the next wheelis not.."'A 'j Another object is to provide an improved. ar* rangement for transmittingv operatingforces to a brake shoe so as to permit that shoe to move laterally with its associated wheel.

A further Objectis to provide an improved linkage fortransmitting motion between generally parallel rods .which are separated by an inter-` y United States No. 2,242,015, granted May 13, 1941,

No. 2,275,916, granted March 10, 1942, and No. 2,360,967, granted October 24, 1944.

My invention is illustrated herein as applied t0 the wheels of a locomotive having two driving trucks of four wheels each. Each wheel is provided with two substantially diametrically opposite brake shoes. ing wheels on each side of a truck may be closely spaced, the front'shoe on each wheel is located above a horizontal. plane passing through the wheel centers, and the rear shoe is located 'below that horizontal plane. `In order' to".obtain the required clearances between the brake structure andthe various parts of the locomotive, Iprovide, for each truck', one brake cylinderand rigging arrangement for operating one group of four shoes on corresponding sides of the four wheels, a second cylinder and rigging arrangement for operating the) two shoes on the opposite sidesof two of the'wheels, and a third brake cylinder and rigging arrangement for operating the two shoes on the opposite sides of the other two wheels.

On both trucks, the front. wheels are arranged` provide an improved In order that the two driv-v to move laterally with respect to the locomotive, and the rear wheels are not. I provide improved compact structure for supporting the front shoe of the rear wheel and the rear shoe of the front wheel, comprising a crank journaled in the locomotive frame and having an arm which carries the' brakehead for the: front shoefof` the rear wheel'. Suitablemeans are provided for rotating this crank to operate that brake shoe. The brake hanger for the rear shoe of the front wheel is universally pivoted on an extension of the crankshaft.

For the front shoes of certain of the wheels which move laterally With respect to the locomotive frame, I provide improved brake operatingl structure including a brake hanger whiclrmoves laterally with the wheels, and a non-rigid con'- nection between the brake hanger and the brake beam which operates it, which connection permits lateral movement of the. hang-er with` respect to the beam while maintaining the operative relationship of the hanger and beam.

The operation ofcertain ofthe brake shoes requires the transmission of motionbetween two parallel rods which are located on opposite sides of an intervening obstruction, inthis casel a steam pipe. I connect these two rods by means of a linkage including four equaliser' levers which in a sense form a rectangle around the steam pipe, although not all locatedA in the same place.

Other objects and characteristic features of. my invention willY become apparent as the descriptionproceeds. i .n y

I shall describe one form of brake' mechanism embodying my invention, and shalll then point out the novel features thereof in claims.

In the accompanying' drawings', Fig. v1 is a side elevational view of the front driving truck' o f a locomotive of the type described having applied thereto brake mechanism' embodying my" invention. Fig. 2 is a fragmentary sectional view taken on the line I l-II of Fig. 1, looking inthe direction of the arrow. Fig. 3 is a fragmentary top plan view of the brake mechanism of Fig. l. ce1'- tain of the parts being omitted for the sake of clearness. Figs. 4, 5, and 6 are fragmentary sectional views taken onthev lines liv-IV, V-V, and VI-VI, respectively, of Fig. 1. Fig'. '7 is a side elevational view of the rear driving truck of the locomotive whose front truck is shown in Fig. 1, having applied thereto' brake mechanism embodying my invention. Figs. 8, 9, and 10 are sectional views taken on the' lines VIII-VIII, IX-IX, and X-X of Fig. 7, respectively, il1ustrating certain details of the brake operating structure. Fig. 1l is a fragmentary top plan View, showing part of thebrake rigging for the front shoe of the front wheel of the truck illustrated in Fig. 7.

The brake mechanism disclosed herein is' for the right side of the locomotive. The left side rigging is for the most part omitted, although certain parts of it are disclosed for the sake of clarity. It should be understood that the omitted portions of the left side rigging are enantiomorphic counterparts of .the corresponding portions of the right side rigging. i

Referring to the drawings, the locomotive to which I have shown my invention applied is of the type having four pairs of driving wheels, numbered l, 2, 3, and {Lrespectively The first and second pairs are driven from a rst set of steam cylinders and the third and foiirth pairs are driven from a second set of steam cylinders. All four pairs of driving wheels are mounted in a rigid frame, which is the frame of the loornotive.

Each pair of driving wheels is mounted on an axle comprising a part of a roller bearing axle assembly, the construction of which forms no part of my present invention, and is therefore not shown in detail in the drawings. The axle assemblies for the first and third pairs of driving wheels! andY 3 are journaled at each end in journal boxes (not shown-) formed' in the member of the frame of the locomotive in such a manner that the journal box is free to slide vertically and laterally with respect to the frame, and each of these two axle assemblies includes a member 5 which connects the two journal boxes and is movable laterally therewith. This member may assume a variety of forms depending upon the particular type of roller bearing construction employed. This member is referred to in the art by a variety of dierent designations, but for convenience I shall hereinafter refer' to it as an axle housing, although it .should be distinctly understood' that insofar as my present invention is concerned its exact construction is immaterial so' long as it is a non-rotatable member which moves laterally in response to lateral movement of the associated driving wheels.

The wheelr and axle' assembly just described is free to move laterally' through a suiiicient distance to permit the wheels to freely follow the track rails on curves'without causing undue side thrust of the flanges of one` or the other of the wheels on the adjacent rails. This lateral dis tance inl actual practice-is about one inch in either directionfrom the normal central position.

The wheel and axle assemblies for the second and fourthv pairs of' driving wheels 2 and 4 are of the usual construction, and are not adapted to move any appreciable distance laterally with respect to the truck frame. Due to the usual operating clear'ar'ic'es these wheels and axle assemblies may at times be' moved laterally, but such movements are' so slight that the assembly at no timel strains the brake rigging or interferes with its proper operation. Insofar as my presentv invention is concerned', the second and fourth wheel and axle assemblies may be ccnsidered as xed against lateral movement.

'Ifhe driving wheels I and 2 of the nrst truck and` 3 and` li' of the second truck are closely spaced, the distance between the Wheels being preferably no greater than that required to keep them clear of one another. The reason for this close spacing is to decrease the overall length of the locomotive to a minimum so as to increase its ability to' negotiate curves.

Front truck-Figs. 1 to 6 The axle housing 5 is provided with two pairs of spaced depending lugs 6 (see Fig. 2). The axle housing 5 alsoy carriesV a spring saddle l to which is attached a bracket 8 having a lug 9 formed thereon. The purpose of the lugs 6 and 9 will appear presently.

The rst pair of drivers i is provided with front brakeheads lil and rear brakeheads il. The second` dri-vers 2 are provided with front brakeheads I2 and rear brakeheads I3. Each brakehead carries the usual brake shoe which brak-inglv engages the surface of the wheel.

The front brakeheads Ill and I2 of the drivers i and 2 on both sides of the truck are operated by a single brake cylinder I4 through its associated rigging. Thepiston (not shown) Within cylinder irl operates a piston rod l5 which is pivotally connected at its outer end to the center of a transverse equalizer lever l G (see Fig. 4), which extends horizontally across the truck. The ends of equalizer lever I6 are vpivotally connected to a pairof vertically disposed brake cylinder levers I1.' The upper ends of the brake cylinder levers I1 are connected by slack vadjuster links I8 of conventional construction, to lugs |80, formed in the locomotive frame. At intermediate points, the brake cylinder levers I1 are connected by pins 4Het to pull links I9. The pins I1a are extended beyond the links I9 in both directions and at their ends carry hardened steel rollers 25, which cooperate with wear plates 2I on the locomotive frame to support the brake cylinder levers I1 and their associated structure.

The opposite ends of the pull links I9 are connected respectively to intermediate points on vertically extending equalizer levers 22. The lower ends of equalizer levers 22 are pivotally connected to links 23. The opposite end of each of the links 23 (only one of which is shown) is pivotally connected (see Fig. 6) to the lower end ofa crank arm 24 carried by a crankshaft 25 journaled in a bearing "blo-ck 26 which is rigidly attached to the locomotive frame. Attached to the outer end of crankshaft 25 is a depending brakehead arm 21 connected by means of a brakehead pin 28 to the brakehead I2 associated with drive wheel 2. Also attached to the outer end of crankshaft 25 is a spring release arm 29, which extends upwardly and is pivotally attached at its end to a spring rod 30, which extends through a lug 3| formed on the locomotive frame, and on the opposite side of lug BI carries a release spring 32 which biases the spring rod 30 in a direction to move the brakehead I2 away'from a brake applying position.

The upper ends of the vertical equalizer levers 22 are pivotally connected to the opposite ends of a second transverse equalizer lever 33. (See Figs. 3 and 5.) The transverse equalizer lever 3'3 is slidably supported on a pair of brackets 34 attached to the locomotive frame, and is pivotally attached at its center to an elongated pull rod 35 which extends forwardly of the locomotive and is pivoted at its other end to a brake beam 36.

A guide arm 31 is pivotally attached to the lugs 9 for rotation about-a horizontal transverse axis, and has its free endreceived in a lug 38 carried by the brake beam 36. vThe guide arm 31 serves to move the brake beam 36 laterally with the movement of the wheel and axle assembly which includes vthe Wheels I.

f The brake beam 36 is supported for swinging movement toward and away from the wheels I by means of Aa pair of supporting levers 39, each of which is provided at its upper end with spaced jaws 4.6 (see Fig. l) to receive one end of the brake beam 36. Each lever 39 is provided at its lower end with otherrspaced jaws 42 which receive a clevis block 44 forming a part of a unversal joint connecting the lever 36 to the locomotive frame. This universal joint structure is more completely described in my previously issuedPatent No. 2,360,967, to which reference has beenmade.A

Pins 45 extend through the Aends of the brake beam 36 and attach it to the upper ends of the supporting levers 39. Each lever-39 carries one of the brakeheads I6 by means of a brakehead pin 46.` Each end of the brake beam 36 is connected by means of a link 41 to a spring release rod 48 which extends through a lugv 49 formed 'on the locomotive frame and carries a release spring 56 by means of suitablel retainers. The release spring 50 biases the brake beam 36 in a direction to Vmove its associated brake shoes. `to a brake releasing position.

SomeV of the complication'ofthe linkage which connects the piston rod I5 to thepull rod 35 is made necessary by the fact that these two rods lie on darnetrically opposite sides of a steam pipe 4I (see Figs. 4 and 5), in the particular locomotive shown here. The generally rectangular arrangement of two horizontal equalizers I6 and 33, and two vertical equalizers 22, and their connecting links, transmits motion around the obstruction between the rods I5 and 35.

vThe rear shoes II on the front drivers I are operated by two brake cylinders 5I through a rigging which includes piston rods 52, brake cylinder levers 53, slack adjuster links 54, a brake beam 59, and brake hangers 55. Each brake hanger 55 is pivotally mounted at its upper end on an extension 25a of the crankshaft 25 (see Fig. 6). The upper end of brake hanger 55 is provided with spaced jaws 56 between which is receivedv a clevis block 51. A pin 58 pivotally connects the clevis block 51 to the spaced jaws 56. The clevis block 51 is in turn pivotally mounted on extension 25a. of4 crankshaft 25 (see Fig. 6). It may be seen that the clevis block 51 provides a type of universal joint support which permits the hanger 55 to swing in a vertical plane between brake applyingjand brake releasing positions, and also to swing transversely of the truck so that the brakehead II may follow the transverse movement of the wheels I.

The lower ends of the hangers 55 are connected by a brake beam 59.

It may be seen from Fig. 6 that the brake hanger 55 lies outside the plane of the wheels I and 2. At its lower end, it is provided with an inwardly directed extension 60, which pivotally carries the brakehead II. The brakeheads II on the opposite sides of the truck are connected by atie rod 6i (see Fig. 2). A guide arm 62 is pivotally mountedin the lugs 6 for rotation about a horizontal transverse axis, and extends through a lug 63 formed on the tie rod 6I. The guide arm 62 and the lug 63 insure that the tie rod and the brakeheads II move laterally as a unit with the axle housing on which the lugs 6 are formed. The brakeheads II are thereby kept in lateral alignment with the wheels I.

The rear brakeheads I3 on the second driver 2 are operated by a .brakecylinder -64 through a rigging which includes a piston rod 65 and a brake cylinder lever 66 extending vertically and pivotally attached at its lower end to the piston rod 65. The lever" 66' is pivotally supported at a point near its upper end on a'lug 61 formed on the locomotive frame. The upper end of brake cylinder lever Il'6jis connected'by a link 68 to the upper end of another vertical lever 63 which extends generally parallel to lever 66. TheA lever 69 is pivotally mounted at an intermediate point nea-r its lower end on the locomotive frame. The lower'end of lever 69 "is pivotally attached to a slack adjuster linkl of conventional con-struction, whoseppposite endis pivotally connected to the mid point `of a brake beam 'IlV extending transversely of the locomotive truck. At itsends, the brake beam 'II is pivotally supported by brake hangers 12, which carry 'the Ibrakeheads I3 by means of brakehead pins 13.

when in is desiredto apply the brakes, num

` pressure is simultaneously supplied to all the brake cylinders I4, 5 I and 64.V The fluid supplied to cylinder I4 moves piston rod I5 to the left, asit appears in Fig. 1, thereby moving equalizer lever i6 to the left and `carrying the lower'ends of brake cylinder leversl'to'the left. Levers I1 rotate about-their upper ends as a fulcrum, carryingthe links I9 to the left and thereby'moving the vertical equalizer levers 22 to the left also. This leftward movement of the equalizer levers 22 is communicated through links 23 to the brakeheads I2 on the front brake shoes of the second driver 2. At the same Itime, it is communicated through the upper transverse equalizer lever 33 and pull rod 35 to brake beam 38 and thereby to the brake supporting levers 39 and brakeheads I9 on the front shoes of the first driver Therefore, it may be seen that all four front shoes of the drive Wheels and 2 are oper ated simultaneously by the brake cylinder I9.

At the same time, brake cylinders act through levers 53, links 5t, and brake beam 59 to operate the rear brakeheads II on the front wheels I. Also, brake cylinder 64 acts through piston rod E5, lever 96, link 68, lever 99, and link 19 to operate brake beam 1| and apply the brake shoes on the brakeheads I3 into braking engagement with the rear drivers 2.

When it is desired to release the brakes, the release springs (not shown) in the several brake cylinders act to move their associated rigging to the brake releasing position. This releasing movement is aided in the case of the front heads I2 by the release springs 32 and in the case of the front heads I by the release springs 5|).

When the front drivers I move laterally, the motion is transmitted through guide arm 31 and brake beam 36 to the front brake supporting levers 39, so that the brakeheads II follow such lateral movement. The lateral movement is also communicated through the guide arm 32 and the tie rod 9 I `to the rear brake shoes I I on the front drivers I. Lateral movement of the front brake hangers 39 and the rear Ibrake hangers 55 asso ciated with the front drivers I is permitted by their universal `ioint suspension including the clevis blocks 44 and 51.

Rear truck-Figs. 7 to 11 Figs. 1 to 11 illustrate the braking mechanism for the rear truck of the locomotive whose front truck is illustrated in Figs; l to 6. This rear truck includes drive wheels 3 and 4. The drive wheels 3 are provided with front brakeheads 't5 and rear brakeheads 16. The drive wheels 4 are provided with front brakeheads 11 and rear brakeheads 18. Each brakehead supports va brake shoe of usual construction.

As in the case of the drive wheels I, the drive wheels 3 are carried in an Vaxle housing generally indicated at 19, and provided with downwardly depending lugs 80. The axle housing 19 also is provided with a bracket 9 I.

The rear lbrakeheads 16' and 18'of both drive wheels 3 and 4 are operated by brake cylinders 82, through rigging which includes push rods 33, cylinder levers B4, slack adjuster links 85, equalizer levers 8S, push connections 81, a brake beam 88 which operates brakeheads 18, a pull rod 89, and brake lbeam 90 which operate brakeheads 18.

' The cylinder levers 84 are pivotally supported on a shaft 9| journaled in bearing blocks 92-cast integrally with the frame of the locomotive. The ends of the brake beam 88 are supported by brake hanger levers 93 which correspond generally to the brake hanger levers 55 of Fig. l and are supported at their upper ends in a similar manner. The lower ends of brake hangers 93 are provided with inward extensions 94 on which the brakeheads 16 are pivoted. The brakeheads 16 on oppcsite sides of the locomotive are connected by a tie rod 95. Near its center this tie red is provided with a lug 9S t0 receive a guide arm 51 pivoted on the lugs 80 attached to the axle housing 19.

The ends of brake beam 99 are supported by brake hanger levers l95| having inward extensions 99 at their lower ends, on which extensions the brakeheads 18 are pivoted by means of brakehead pins |09.

The brakeheads 15 are operated by a brake cylinder I8| through a linkage including a piston rod |92, a brake cylinder lever |03, a push connection I |719 (see Fig. 11), and a brake beam |05. Each end of brake beam |95 carries a horizontally extending adjusting screw I 96 held in place in the brake beam |95 by means of lock nuts |91. Each brakehead 15 is pivotally attached to a brake supporting lever |98. The levers I 98 are mounted at their lower ends on universal joints I 99 which permit the brakeheads 15 to follow the lateral movement of the wheels 3. Near its vupper end, each lever |98 is provided with a wear plate I|I| in alignment with the head of adjusting screw |96. Each wear plate IIE) is wider than its associated adjusting screw I 95, so that as the brake hangers I 98 move laterally with the wheels 3, the wear plates |I9 remain in alignment with the screws |99, even though the screws I 9B and the brake Ibeam |95 do not mov-e laterally.

At its upper extremity, each lever |98 is provided with an apertured lug to receive a spring rod |I2. The rod |i2 is pivotally connected at one end to a bracket |I3 attached to the locomotive frame. On the opposite side of lug III from the bracket IIS, the rod II2 carries a release spring I i9. Suitable retainers are provided on the spring rod I I2 for retaining the release spring IIA. The release spring IIll vbiases the supporting lever |98 in a brake releasing direction, and so maintains the wear plate IIU in engagement with the head of adjusting screw |06. The brake beam |95 is supported in brackets |I5 attached to the locomotive frame.

The brake-heads 15 on opposite sides of the truck are connected by means of a tie rod IIS. A guide arm ||1 is pivoted at one endon the bracket 9| of the axle housing 19 and is received at its opposite end in a lug on the tie rod I I5. The guide arm I|1 insures that the tie rod IIS, together with the brakeheads 15 and the brake hangers E98 move laterally with the lateral movement of the wheels 3 and their axle housing 19.

The brakeheads 11 associated with the front shoes of the drive wheels 9 are operated by a brake cylinder' I I8'. The cylinder H8 drives a piston rcd I|9 (see Fig. 9) connected at its outer end to the mid point of an equalizer lever |29. The ends of equalizer lever I 29 are pivotally connected to pull rods |2I, whose opposite ends are pivotally attached to vertically disposed brake cylinder levers in the form of bell-crank levers |22. The bell crank lever. |22 has a long arm connected to the pull rod I2I and a short arm connected through a slack adjuster trunnion |23 to a push rod I2. The other end of push rod |24 is pivotally connected to a crank arm |25 xed on a crankshaft |29, which is journaled in a bearing block |21 (see Fig. 10) attached by suitable means to the frame of the locomotive. The crankshaft |26 carries a brakehead arm |28, on which the brakehead 11 is pivoted by means of a brakehead pin |29. The crankshaft |25 also carries a release spring arm |30 pivotally attached at its end to a spring rod I3I. The rod rI3I extends through `a lug I32 connected to the locomotive frame and carries a release spring I33by means of suitable spring retainers. The

vrelease spring |33 acts through rod I3I and arm |30 to bias the brakeheads 11 for movement in a brake releasing direction. The construction of crankshaft |26 and its related parts is generally similar to that of crankshaft 25` of Figs. 1 and 6.

The brakes are applied on both trucks simultaneously. The application of the brakes on the rear Vtruck is accomplished by supplying fluid under pressure to the cylinders 82, II'II, and H8. The cylinders 82 act through the push rods 83, cylinder levers 84, slack adjuster links `85, equalizers 88, push connections 8l', and brake beams 88 to operatethe rear brakeheads 'I6 on the wheels 3, to braking position. At the same time, the same cylinders 82 act through equalizers k88, pull rod 89 and brake beam 99 to operate the brakeheads I8 on the wheels 4 to braking position. Y

Simultaneously, cylinder lill operates cylinder lever H13, push connection |04, and brake beam |85, to move the adjusting screws |86 and thereby the brake supporting levers |08 and brakeheads 'l5l into braking position. At the same time, the brake cylinder II8 operates through pull links i2i, bell-crank levers |22, push rods I24, crank arms I25, crankshafts |26, and brakehead arms |23 to operate the brakeheads 'I5 into braking position. l Y

When it is desired to release the brakes, the several cylinders are exhausted to atmosphere. At this time, the internal springs in the various cylinders move the brakeshoes to brake releasing position. This releasing action is aided in the 91 acting through the tie rod 95 on the `brakeheads '53. i

Although I have herein shown and described only one form of brake mechanism embodying my invention, it is understood .that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. Brake mechanism for awheel, comprising a crankshaft, a brake shoe adapted to brakingly engage the wheel, a brakehead for supporting the shoe, a brakehead arm on the crankshaft and pivotally supporting the brakehead, means for rotating the crankshaft to bring the shoe into braking engagement with thewheel, a release spring arm on the crankshaft, and a release pring basingthe armin a brake releasing direc- 2.. Brake `mechanism fora pair of Wheels on opposite ends of an axle, comprising a brake cylinder and piston, an equalizer lever extending generally parallel to the axle, a piston rod conn-ecting the piston to an intermediate point on the equalizer lever, and, for each wheel, a brake cylinder lever operatively connected to one end of the equalizer lever, a crankshaft, a crank arm on the crankshaft, a linkage connecting the brake cylinder lever to the crank arm, a brake shoe l0 adapted to brakingly engage the wheel, a brakehead supporting the shoe, and a brakehead-arm on the crankshaft and pivotally supporting the brakehead.

3. Brake mechanism for a vehicle wheel, comprising a brake cylinder and piston, a piston rod for said piston, a brake cylinder lever operatively connected at one end to the piston rod, a slack adjuster link connecting the other end of the brake cylinder lever to a pivot -xed on the vehicle, a crankshaft, a crank arm on the crankshaft, a linkage connecting an intermediate point on the brake cylinder lever to the crank arm, a brake shoe adapted to brakingly engage the wheel, a brakehead for supporting the shoe, and a brakehead arm on the crankshaft and pivotally supporting the brakehead.

4. Brake mechanism for a wheel, comprising a brake cylinder and piston, a pistonv rod for said piston, a bell-crank lever having one arm operatively connected to the piston rod, a crankshaft, a crank arm on the crankshaft, a slack adjuster link connecting the other arm of the bellcrank lever to the crank arm, a brake shoe adapted to brakingly engage the wheel, a brakehead for supporting the shoe, and a brakehead arm on the crankshaft and pivotally supporting the brakehead.

5. Brake mechanism for operating brake shoes on the same sides of the wheels at the opposite ends of an axle, comprising a brake cylinder and piston, a first transverse equalizer lever, a piston rod connecting the piston to an intermediate point on the equalizer lever, a pair of vertical equalizer levers, means operatively connecting the ends of the transverse equalizer lever to intermediate points on the vertical equalizer levers, a second transverse equalizer lever connected at its ends to the upper ends of said vertical equalizer levers, and a pair of linkages connecting the lower ends of the vertical equalizer levers with the brake shoes, each said linkage comprising a crankshaft, a crank arm on the crankshaft, a link connecting the lower end of the vertical equalizer lever to the crank arm, a breakhead supporting the shoe, and a brakehead arm on the crankshaft and pivotally supporting the brakehead.

6. Brake mechanism for a four-wheel truck having brake shoes on the same sides of all four wheels comprising a brake cylinder and piston, a first transverse equalizer lever, a piston rod connecting the piston to any intermediate point on the equalizer lever, a pair of vertically disposed cylinder levers connected to the opposite ends of the equalizerlever, a pair of vertical equalizer levers extending generally parallel to the respective cylinder levers, a pair of links, each link connecting an intermediate point on one cylinder lever to an intermediate point on the associated vertical equalizer lever, a pair of linkages connecting the lower ends of the vertical equalizerv levers with the brake shoes on one pair of opposite wheels on the truck, a ,second transverse equalizerlever connected atits ends to the upper ends of said vertical equalizer levers, means including a brake beam operatively connecting the brake shoes on the other pair of cpposite wheels on the truck, and a rod pivotally connected at one end to an intermediate point on said second transverse equalizer lever and at its opposite end to an intermedi-ate point on said brake beam.

7. Brake mechanism for a vehicle truck having two wheels on one side, two brake shoes located between said wheels for respectively engaging said wheels, a brakehead for each shoe, a crankshaft, a brakehead arm on said crankshaft and pivotally carrying one of said brake shoes, a brake hanger rotatable on said crankshaft and pivotally carrying the other of said brake shoes, means for rotating said crankshaft to operate said one brake shoe, and means for swinging the brake hanger to operate the other brake shoe.

8. Brake mechanism for a vehicle truck having closely spaced wheels, comprising upper and lower brake Yshoes located between the wheels and respectively above and below the point 'of minimum clearance between the wheels, a brakehead for each "shoe, va crankshaft, a brakehead arm on said crankshaft and pivotally carrying one of said brake shoes, a brake hanger rotatable on said crankshaft and pivotall'y carrying the other of said brake shoes, means for rotating said crankshaft to operate said one brake shoe, and means for swinging Athe brake hanger to operate the other brake shoe.

9. Brake mechanism for operating brake shoes on the same sides of the wheels at the opposite ends of an axle, comprising a brake beam connecting said shoes, a brake cylinder and piston supported horizontally at right angles to said beam and in alignment with the center thereof., a brake cylinder lever extending generally vertically and fulcrumed at 'an intermediate point nearer its upper end than its lower end, a second lever extending generally parallel to lsaid brake cylinder lever and fulcrumed at an intermediate point nearer its lower than its upper end, a piston rod connecting the piston and the lower end of the brake cylinder lever, a link connecting the upper ends of the levers, and a link connecting the lower end of the second lever and the center of the brake beam.

10. Brake mechansim for a vehicle having a a wheel mounted thereon for limited lateral movement with respect thereto, comprising a brake shoe adapted to brakingly engage the wheel, a brakehead for supporting the shoe, a brake hanger for pivotally supporting the brakehead, a universal joint connecting the hanger to the vehicle to permit the head and hanger to follow the lateral movements of the wheel, a member movable to engage the hanger and move it into braking position, and means for operating said member to apply the brake shoe to the wheel, said hanger having a surface facing and substantially wider than said member so that the member engages said surface in all lateral positions of the hanger.

l1. Brake 'mechanism for a vehicle having a wheel mounted thereon for limited lateral movement with respect thereto, comprising a brake shoe adapted to brakingly engage the wheel, a brakehead for supporting the shoe, a brake hanger for vpivotally supporting the brakehead, a universal joint connecting the hanger to the vehicle to permit the head and hanger to follow the lateral movements of the wheel, a release spring biasing the hanger in va direction to disengage the brake sh'oe from the wheel, a member movable to engage the hanger and move it into braking 1'2 position in opposition to the release spring, and means for operating said member to apply the brake shoe to the wheel, said hanger having a surface facing and substantially wider than said member so that the member engages said surface in all lateral positions of the hanger.

12. Brake mechanism for a vehicle having a pair of opposite wheels mounted thereon for limited lateral movement with respect thereto, comprising a brake shoe for each wheel, a brakehead for supporting each shoe, a brake hanger for pivotalli7 supporting ea'ch `brakehead, a universal joint connecting each hanger to the vehicle to permit the head and hanger to follow the lateral movements of 'the wheel, a release spring biasing each hanger in a direction to disengage its brake shoe from its associated wheel, a member movable to engage each hanger and move it into braking position in opposition to the release spring, a brake beam carrying the movable members for both of said hangers, means for operating said 'beam to apply the brake shoes to the wheels, said hangers vhaving surfaces facing and substantially Wider than said members so that the meinbers engage said surfaces in all lateral positions of the hangers, a tie rod connecting Athe hangers on the opposite wheels land a `guide connecting the tie rod to a -fulcrum movable laterally with the wheels, `so that the wheels, hangers, tie rod and guide Vmov-e laterally together.

13. In a brake mechanism for a railway vehicle, a linkage for transmitting motion between two generally parallel rods located on opposite sides ci an obstruction, comprising a first equalizer lever pivoted at its center on one of said rods, second and third equalizer levers located in planes generally perpendicular to said iirst equalizer lever, 4means operatively yconnecting the ends of said rst lever with points on said second and third levers, fulcrum means connected to said second and third levers at other points thereon, a fourth equalizer lever generally parallel to said iirst lever and pivoted at its center to the other of said rods, and means operatively connecting the ends of said fourth lever with points on said second and third levers.

EMIL G. MUELLER.

REFERENCES CITED The following references are of record in the file `of 'this patent:

UNITED STATES PATENTS Number Name Date 1,820,723 Anderson Aug. 25, 1931 1,914,595 Grossman June 20, 1933 2,159,126 Repka Aug. 8, `193.9 2,242,015 Mueller May 13, 1941 2,244,215 Pescara June 3, l1941 y2,275,916 Mueller Mar. 10, '1942 2,360,967 Mueller Oct. 24, 15244 2,406,446 Sauer Aug. 27, y194el Number Country Date 14,341- Great Britain 1904 

